Impedance spectroscopy as a tool to monitor the adsorption and removal of nitrate ions from aqueous solution using zinc aluminum chloride anionic clay

In this study, Zn3AlCl ionic clay was used to investigate the adsorption mechanism of the nitrate ions in solutions containing nitrate ions at different contact time. The clay was synthesized by coprecipitation method at room temperature, and this sample was characterized by XRD, Fourier transform-infrared (FT-IR) and inductively coupled plasma (ICP). This sample was crystallized in a rhombohedral symmetry (Space group: R-3 m). Impedance spectroscopy was used as a tool to evaluate and monitor the adsorption process at different contact time 5; 10; 20; 30; 60 min and the clay alone. The impedance measurement was well analyzed and fitted with an equivalent circuit containing both (R//CPE) connected in series. Furthermore, the σac conductivity was also investigated as a function of frequency. It was analyzed and fitted using double power law: σac(ω)=σdc+Aωs1+Bωs2,(0≤s1≤1and0≤s2≤1). This study reveals the existence of two relaxation processes with different relaxation times, which could be attributed to the grain and grain boundaries, and exhibit high values of dielectric constant at low frequencies

Disinfection of dental impressions: knowledge and practice among dental technicians

Noor Al Mortadi,1 Aceil Al-Khatib,2 Karem H Alzoubi,3 Omar F Khabour41Department of Applied Dental Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, Jordan; 2Department of Oral Medicine and Oral Surgery, Faculty of Dentistry, Jordan University of Science and Technology, Irbid, Jordan; 3Department of Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan; 4Department of Medical laboratory Sciences, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, JordanBackground: Dental impressions are a common source for transmission of infection between dental clinics and dental labs. Dental impressions can be cross-contaminated by patient’s saliva and blood, which then cross-infect the dental casts poured from the impressions.Objective: To evaluate the current practices of disinfection of dental impressions and their protocols and to assess the knowledge of cross-infection control among dental technicians in Jordan.Method: Dental technicians (n=85) completed a self-administered questionnaire about their practices of disinfection for dental impressions.Results: The distribution of dental technicians was 63.8% fixed prosthodontics, 23.5% removable prosthodontics, 7.8% orthodontics, and 4.8% maxillofacial prosthodontics. The majority of the laboratories did not have instructions related to disinfection of impressions. About 50% of technicians were vaccinated against HBV. About 44.7%, and 42.9% of labs reported that they never disinfect alginate or silicon impressions, respectively. In addition, the majority of lab owners (53%) believed that the dentist should disinfect the impressions before shipping them to dental laboratories, while (45%) believed that disinfecting the impressions is the responsibility of the dental assistant. Moreover, about 38% of this study population reported not using gloves in their labs. In those labs were disinfection was used, 51% used spray disinfection whereas 32.6% used immersion disinfection. The cost of disinfectant was ranked as the most important factor (51.3% of the cases) for the dental technician to choose the disinfectant followed by its effectiveness.Conclusion: Dental technician practices in impression disinfection was not satisfactory, therefore, education programs about impression disinfection are needed.Keywords: disinfection, dental impressions, knowledge, practice, dental technician